air bubbles

I am moving from component pen making to fully custom pens and needed to increase the lengths of my blanks to accommodate the change. I watched a great video from John Underhill on vertical pen blank casting using his system and I decided to purchase it. Works very well, but I am having a...

I'm very new to casting blanks but have been around epoxy for a while. Mostly for making scale radio control airplanes. I've never seen this. Alumilite Clear Slow. New bottles so it shouldn't be old since I ordered directly from Alumilite. Mixol pigments I picked up at Rockler. I used the Red...

I need help with castings getting numerous air bubbles. I have always used air pressure and I tried these casting materials from Polytek, Kraft, and Turtle Feathers. I am trying to cast with coal dust and Inlace (black dye) from Turtle Feathers, I have used PVC and pink rubber molds.